1. Field of the Invention
The present invention relates to energy storage device, and particularly to an elastic energy storage device having a plurality of spiral springs and a flywheel for storing energy and then releasing the energy steadily.
2. Description of Related Art
Referring to FIGS. 1 and 2, a portable manual generator is disclosed in Taiwan Patent No. 86208974. This prior art includes a casing, a generator, a driving portion, and an actuating portion. The driving portion includes a plurality of gears. One side of the actuating portion is engaged to the gear of the driving portion and another side thereof protrudes out of the casing. A lower end of the actuating portion has an elastic element which drives the actuating portion to moving reciprocally. Thereby, when the driving portion is pressed continuously, the gear of the driving portion can be driven and then the gear of the driving portion drives the generator so that the rotor of the generator rotates with a high speed to generate electric power. However, the power generated by this way can not be stored and thus the user must press the actuating portion continuously for generating power. Once the user stops the operation, the power is interrupted. Moreover, since the electric power from the generator is generated by the manual action, if the user can not steadily operate the generator, then the output power and frequency is unstable.